The two most popular self defense weapons are the Talon Mini 625 volt and the Stun Master 625,000 volt stun gun. The stun gun is a very effective weapon that works with a 9-volt Ni-Cad rechargeable battery. Other batteries like the alkaline batteries too can be used but you cannot use the regular batteries in these stun guns.  

You will be astonished to know that even law enforcing agencies use stun guns saddled with lifetime lithium batteries. Due to its effectiveness and ability to immobilize any intruder within seconds of contact, the stun gun is now highly preferred over many other self defense products. 

The Stun Master 625,000 volt is a 7-3/4 inch long and 2 inch wide device that contains ¼ inch electrodes. Unlike the distant spray devices like the mace pepper spray it is basically a contact device that creates impact on physical contact. The good news is that even a 15-30 second contact may create a 5-10 minutes impact but the weapon is not lethal. 

For the purpose of safety there is a safety switch, wrist strap and you can keep it inside the holster with a belt loop.  

However, there is one cliché in all these. The stun guns may not be legal in your place and you must check this out with the local authorities. Wherever it is legal, a combination of devices like the door stop alarm and Stun Master 625,000 volt can be extremely useful for the security of your premises.